I have 1961 Gtb insert that is over 1” in diameter. It is pretty concave. Someone mentioned a method of flattening it using a heat gun. Anyone know the link to the method?
All I could find is the PinballHelp video that suggests sanding. Don’t think it would work on a large, concave piece.
You can level inserts with a heat gun, not fix cupping. Can you find the right size insert new from marcos or pinball life? If you can, heat the insert from and push it out of the playfield and replace it with the new one.
Here’s a link to a method. I did something similar (though used a hair dryer instead of a heat gun) as described in the post to flatten a large (1-1/2” or 2”) insert from an early 1950s machine. In my case, the insert had three supports in the bottom of it that radiated out from the center (that presumably were in place to prevent it from warping) and so there wasn’t an easy way to use a socket to press down at the center of the insert. Instead I used a smaller socket to press in the flat areas between the supports. It took a while to flatten and lots of repeated steps of heating and pushing, but the insert ultimately came out well and has remained flat after having done this several years ago.
Good luck!
Quoted from jibmums:Here's how I flattened mine once I had them out of the playfield. You'll need a heat gun this time, the same 1/4" socket driver, and a small cup of very cold water. Lay the insert face down on a clean, flat, heat-proof surface like a granite countertop. Keeping the heat gun 8" or so away, you want to heat the insert as if you were spray painting it. In other words, don't just hold the gun on it in a stationary position, because you'll surely deform or even melt it. Move the gun and make "passes" over the insert, just like it was a model car and you were spray painting the body.
You want the plastic heated to the point where it's warmed/softened enough that the pressure you're going to apply with the socket driver will force it down/flat, but not so warm that the vertical sides, usually the thinnest part of the insert, deform. That's why you want to go carefully with the heat until you develop your rhythm for how to heat the insert. After several passes, take your socket driver and gently but firmly press down in the center of the insert. When it's sufficiently heated, you'll see it flatten down from the pressure you apply with the socket driver. Move the driver around in the insert to flatten as much of the area as you can. Then position it in the middle and holding it firmly down, pour enough cold water on the insert to fill it and to create a small puddle around it. Keep pressing gently for a minute or so while the water cools and hardens the insert, then remove the driver and let the insert sit in the puddle for a couple minutes, then dry and move on to the next one.
This method worked very well for me, and it was the first time I'd ever tried it. I need to stress again though, make passes with the heat gun instead of holding it in one spot! While it doesn't make the inserts perfectly flat (only sanding would do that) it eliminates all/most of the banana shape. And if you do then sand them, you'll need to remove less material to flatten them entirely.
https://pinside.com/pinball/forum/topic/the-firepower-club/page/3#post-1611379
Thanks. If this doesn’t work, I’ll try buying a new one. Ordered the wrong insert by mistake and wanted to get to the project while I’m on a short break.
Oops… the insert fits very loosely now, even the surface, which you wouldn’t expect to shrink with time.
A new one fits tightly. Too bad I bought the wrong one- got a faceted one by mistake. Correct one is on its way from Marcos.
New one will be a shade lighter, but I guess it’s better than using wood epoxy to fit the old one.
Heated the old one, stretched out the sides with a socket wrench. Polished with Novus. If the glue holds, we're good.
Here's what worked for me:
I used a ceramic tile on my table. I also used a screwdriver with a plastic handle that pretty much fit inside the insert with a little room to move around. Didn’t use a socket because I didn’t want cold metal that would cool down the plastic insert immediately.
With the insert face up on the tile, heat with heat gun on low about 4" - 8” away , moving the heat around. I did it face up so the surface would soften but not so much the sides. After about 10-15 seconds, flip it over and press down with the screwdriver handle. Keep pressing until you think the plastic has cooled. Flip it right side up and place a pinball on it. That shows you if you are good or need to keep working on it. You might have to repeat & press flat with the screwdriver in another place.
If the sides of the insert are warped, you can use the heat and something round like a wooden dowel to work it back into shape.
I was working on inserts from a 1961 Gottlieb. Your mileage may vary.
Simple way to fix cupping on inserts. Super easy and they do their job.
TheEMScoreKeeper.com $5 for a full set of Invisible Mylar Insert Stickers. Free shipping.
Quoted from ThePinScientist:Simple way to fix cupping on inserts. Super easy and they do their job.
TheEMScoreKeeper.com $5 for a full set of Invisible Mylar Insert Stickers. Free shipping.
You are simply trying to use mylar to accomplish filling or replacing. I do understand what you are selling and for many people, is a reasonable solution.
It depends on your perspective of what pinball is and what you can live with. The playfield is manufactured to be a flat surface and as we all know and cupped inserts ruin the playing experience.
If an insert is severely cupped, a single layer of mylar will droop over time. Stacking the mylar to get the result flatter is needed using varying sizes as stated in your video.
Not all inserts are created equal. Maybe someone else can shed light on why but from my experience Gottlieb cupping is far less pronounced than Williams or Bally's of the same era.
You see lots of forum posts about a Gottlieb insert that simply falls out or has suffered severe shrinkage. The inserts tend to be pretty easy to pop out. I'm not sure if the plastic they used was from a different supplier than William's but I doubt it.
I'm in the process of restoring an Aztec and have replaced the inserts due to severe cupping commonly seen on William's. I would assume that William's playfield insert hole diameter was slightly smaller than Gottlieb's. Getting inserts out when this tight can risk cracking/delaminating the plywood at the insert location.
I hate dealing with inserts as much as the next guy. Even tried using a heat gun to flatten them out. Now this does work, but to a limited degree. Can't get it perfect but you can reduce deep cupping this way. In fact, I might suggest doing this first then the mylar for a better result on really bad inserts if you can't replace them.
What I'd love to see is an easy yet durable long term solution that easy enough for anyone to do. The closest thing I've seen is the windshield epoxy cured with UV. Haven't tried this yet but looks interesting.
But please don't be dismissive of reality and state your product "fixes" cupped inserts. It alleviates the issue but doesn't resolve it.
Quoted from Garrett:You are simply trying to use mylar to accomplish filling or replacing. I do understand what you are selling and for many people, is a reasonable solution.
It depends on your perspective of what pinball is and what you can live with. The playfield is manufactured to be a flat surface and as we all know and cupped inserts ruin the playing experience.
If an insert is severely cupped, a single layer of mylar will droop over time. Stacking the mylar to get the result flatter is needed using varying sizes as stated in your video.
Not all inserts are created equal. Maybe someone else can shed light on why but from my experience Gottlieb cupping is far less pronounced than Williams or Bally's of the same era.
You see lots of forum posts about a Gottlieb insert that simply falls out or has suffered severe shrinkage. The inserts tend to be pretty easy to pop out. I'm not sure if the plastic they used was from a different supplier than William's but I doubt it.
I'm in the process of restoring an Aztec and have replaced the inserts due to severe cupping commonly seen on William's. I would assume that William's playfield insert hole diameter was slightly smaller than Gottlieb's. Getting inserts out when this tight can risk cracking/delaminating the plywood at the insert location.
I hate dealing with inserts as much as the next guy. Even tried using a heat gun to flatten them out. Now this does work, but to a limited degree. Can't get it perfect but you can reduce deep cupping this way. In fact, I might suggest doing this first then the mylar for a better result on really bad inserts if you can't replace them.
What I'd love to see is an easy yet durable long term solution that easy enough for anyone to do. The closest thing I've seen is the windshield epoxy cured with UV. Haven't tried this yet but looks interesting.
But please don't be dismissive of reality and state your product "fixes" cupped inserts. It alleviates the issue but doesn't resolve it.
I understand what you are trying to say. But, I have to say my wording on the product is not being untruthful. It totally can help fix the issue of cupping and for a long time (years). I think you're pulling hairs here. I understand replacing the insert is the best option and will last the longest (if done correctly). I totally believe this should be done, if the owner feels they have the skill set to do this. I feel like with these stickers, it's protecting the playfield and preserving the pin's inserts, while improving the cupped or recessed inserts. It's a valid solution for most casual pin owners that don't have the skills or the time to replace or restore the inserts themselves. It might not last 20 years, but I wouldn't be surprised if these did.
You can't dispute that it works, and protects very well. It doesn't hurt anything on the pin. It is a fix, but it might not be the best fix to some. That we should both be able to meet in the middle on. If you still don't agree, that's fine. Everyone can have an opinion. I can respect that.
Wanna join the discussion? Please sign in to reply to this topic.
Great to see you're enjoying Pinside! Did you know Pinside is able to run without any 3rd-party banners or ads, thanks to the support from our visitors? Please consider a donation to Pinside and get anext to your username to show for it! Or better yet, subscribe to Pinside+!
This page was printed from https://pinside.com/pinball/forum/topic/how-to-flatten-concave-inserts and we tried optimising it for printing. Some page elements may have been deliberately hidden.
Scan the QR code on the left to jump to the URL this document was printed from.
Boise, ID